Abstract
Toll-like receptors (TLRs) functionally expressed in salivary epithelial cells, but their roles remain elusive. Among TLRs family, TLR3 is activated by dsRNA, a byproduct of viral infection. The aim of this study was to investigate the role of TLR3 in the inflammatory immune responses using HSG cells. Reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR and ELISA were performed to identify expression of TLRs and TLR3-mediated chemokine inductions. The chemotaxis assay of activated T lymphocytes was also performed. Treatment of HSG cells with polyinosinic: polycytidylic acid (poly(I:C)) significantly increased interferon-γ-inducible protein 10 (IP-10), interferon-inducible T-cell α chemoattractant (I-TAC), and regulated on activation, normal T-cells expressed and secreted (RANTES) gene expressions in a concentration-dependent manner. Anti-TLR3 antibody blocked the increases of IP-10 and I-TAC genes. Poly(I:C)-induced increases of IP-10 and I-TAC were also confirmed at protein levels from cell lysates, but their release into extracellular medium was detected only in IP-10. We found that the culture media from HSG cells stimulated with poly(I:C) significantly increases T lymphocyte migration. Our results suggest that TLR3 plays an important role in chemokine induction, particularly IP-10, in salivary epithelial cells.
References
2. Matsukura S, Kokubu F, Kurokawa M, Kawaguchi M, Ieki K, Kuga H, Odaka M, Suzuki S, Watanabe S, Takeuchi H, Kasama T, Adachi M. Synthetic double-stranded RNA induces multiple genes related to inflammation through Toll-like receptor 3 depending on NF-kappaB and/or IRF-3 in airway epithelial cells. Clin Exp Allergy. 2006; 36:1049–1062.
3. Proost P, Vynckier AK, Mahieu F, Put W, Grillet B, Struyf S, Wuyts A, Opdenakker G, Van Damme J. Microbial Toll-like receptor ligands differentially regulate CXCL10/IP-10 expression in fibroblasts and mononuclear leukocytes in synergy with IFN-gamma and provide a mechanism for enhanced synovial chemokine levels in septic arthritis. Eur J Immunol. 2003; 33:3146–3153.
4. Ritter M, Mennerich D, Weith A, Seither P. Characterization of Toll-like receptors in primary lung epithelial cells: strong impact of the TLR3 ligand poly(I:C) on the regulation of Toll-like receptors, adaptor proteins and inflammatory response. J Inflamm (Lond). 2005; 2:16.
5. Greene CM, McElvaney NG. Toll-like receptor expression and function in airway epithelial cells. Arch Immunol Ther Exp (Warsz). 2005; 53:418–427.
6. Schaefer TM, Fahey JV, Wright JA, Wira CR. Migration inhibitory factor secretion by polarized uterine epithelial cells is enhanced in response to the TLR3 agonist poly (I:C). Am J Reprod Immunol. 2005; 54:193–202.
7. Fox RI, Kang HI, Ando D, Abrams J, Pisa E. Cytokine mRNA expression in salivary gland biopsies of Sjogren's syndrome. J Immunol. 1994; 152:5532–5539.
8. Ramos-Casals M, Munoz S, Medina F, Jara LJ, Rosas J, Calvo-Alen J, Brito-Zeron P, Forns X, Sanchez-Tapias JM. Systemic autoimmune diseases in patients with hepatitis C virus infection: characterization of 1020 cases (The HISPAMEC Registry). J Rheumatol. 2009; 36:1442–1448.
9. Prunoiu C, Georgescu EF, Georgescu M, Simionescu C. Sjogren's syndrome associated with chronic hepatitis C – the benefit of the antiviral treatment. Rom J Morphol Embryol. 2008; 49:557–562.
10. Park C, Lee S, Cho IH, Lee HK, Kim D, Choi SY, Oh SB, Park K, Kim JS, Lee SJ. TLR3-mediated signal induces proinflammatory cytokine and chemokine gene expression in astrocytes: differential signaling mechanisms of TLR3-induced IP-10 and IL-8 gene expression. Glia. 2006; 53:248–256.
11. Ohyama Y, Carroll VA, Deshmukh U, Gaskin F, Brown MG, Fu SM. Severe focal sialadenitis and dacryoadenitis in NZM2328 mice induced by MCMV: a novel model for human Sjogren's syndrome. J Immunol. 2006; 177:7391–7397.
12. Kawakami A, Nakashima K, Tamai M, Nakamura H, Iwanaga N, Fujikawa K, Aramaki T, Arima K, Iwamoto N, Ichinose K, Kamachi M, Ida H, Origuchi T, Eguchi K. Toll-like receptor in salivary glands from patients with Sjogren's syndrome: functional analysis by human salivary gland cell line. J Rheumatol. 2007; 34:1019–1026.
13. Spachidou MP, Bourazopoulou E, Maratheftis CI, Kapsogeorgou EK, Moutsopoulos HM, Tzioufas AG, Manoussakis MN. Expression of functional Toll-like receptors by salivary gland epithelial cells: increased mRNA expression in cells derived from patients with primary Sjogren's syndrome. Clin Exp Immunol. 2007; 147:497–503.
14. Sauty A, Dziejman M, Taha RA, Iarossi AS, Neote K, Garcia-Zepeda EA, Hamid Q, Luster AD. The T cell-specific CXC chemokines IP-10, Mig, and I-TAC are expressed by activated human bronchial epithelial cells. J Immunol. 1999; 162:3549–3558.
15. Qin S, Rottman JB, Myers P, Kassam N, Weinblatt M, Loetscher M, Koch AE, Moser B, Mackay CR. The chemokine receptors CXCR3 and CCR5 mark subsets of T cells associated with certain inflammatory reactions. J Clin Invest. 1998; 101:746–754.
16. Doyle S, Vaidya S, O'Connell R, Dadgostar H, Dempsey P, Wu T, Rao G, Sun R, Haberland M, Modlin R, Cheng G. IRF3 mediates a TLR3/TLR4-specific antiviral gene program. Immunity. 2002; 17:251–263.
17. Doyle SE, O'Connell R, Vaidya SA, Chow EK, Yee K, Cheng G. Toll-like receptor 3 mediates a more potent antiviral response than Toll-like receptor 4. J Immunol. 2003; 170:3565–3571.
18. Cole KE, Strick CA, Paradis TJ, Ogborne KT, Loetscher M, Gladue RP, Lin W, Boyd JG, Moser B, Wood DE, Sahagan BG, Neote K. Interferon-inducible T cell alpha chemoattractant (I-TAC): a novel non-ELR CXC chemokine with potent activity on activated T cells through selective high affinity binding to CXCR3. J Exp Med. 1998; 187:2009–2021.
19. Deshmukh US, Nandula SR, Thimmalapura PR, Scindia YM, Bagavant H. Activation of innate immune responses through Toll-like receptor 3 causes a rapid loss of salivary gland function. J Oral Pathol Med. 2009; 38:42–7.
20. Szodoray P, Alex P, Brun JG, Centola M, Jonsson R. Circulating cytokines in primary Sjogren's syndrome determined by a multiplex cytokine array system. Scand J Immunol. 2004; 59:592–599.
21. Ogawa N, Ping L, Zhenjun L, Takada Y, Sugai S. Involvement of the interferon-gamma-induced T cell-attracting chemokines, interferon-gamma-inducible 10-kd protein (CXCL10) and monokine induced by interferon-gamma (CXCL9), in the salivary gland lesions of patients with Sjogren's syndrome. Arthritis Rheum. 2002; 46:2730–2741.
22. Zhou W, Dong Y, Zhao Y, Tang FL. Abnormal interferon-inducible protein-10 expression in the labial glands of patients with Sjogren's syndrome. Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2003; 25:603–607.
23. Ogawa N, Shimoyama K, Kawanami T. Molecular mechanisms of salivary gland destruction in patients with Sjogren's syndrome. Nihon Rinsho Meneki Gakkai Kaishi. 2005; 28:10–20.
24. Kasman LM, London LL, London SD, Pilgrim MJ. A mouse model linking viral hepatitis and salivary gland dysfunction. Oral Dis. 2009; 15:587–595.
25. Hasegawa H, Inoue A, Kohno M, Muraoka M, Miyazaki T, Terada M, Nakayama T, Yoshie O, Nose M, Yasukawa M. Antagonist of interferon-inducible protein 10/CXCL10 ameliorates the progression of autoimmune sialadenitis in MRL/lpr mice. Arthritis Rheum. 2006; 54:1174–1183.
26. Kim SK, Kim YM, Yeum CE, Jin SH, Chae GT, Lee SB. Rifampicin Inhibits the LPS-induced Expression of Toll-like Receptor 2 via the Suppression of NF-kappaB DNA-binding Activity in RAW 264.7 Cells. Korean J Physiol Pharmacol. 2009; 13:475–482.